Active I/O switches in system area networks

We present an active switch architecture to improve the performance of systems connected via system area networks. Our programmable active switches not only flexibly route packets between any combination of hosts and I/O devices, but also have the capability of running application-level code, forming a parallel processor in the SAN subsystem. By replacing existing SAN-based switches with a new active switch architecture, we can design a prototype system with otherwise commercially available, commodity parts that can dramatically speed up data-intensive applications and workloads on modern multi-programmed servers. We explain the programming model and detail the microarchitecture of our active switch, and analyze simulation results for nine benchmark applications that highlight various advantages of active switch-based systems.